To fully understand the spectral response characteristics of powdery mildew (PM) on winter wheat, in-situ hyperspectral data were collected and comparatively analyzed. The center distance method was ...first used to remove the abnormal spectral response bands using the red-edge position. Subsequently, the Relief-F algorithm and correlation analysis were jointly introduced to identify the best bands sensitive to the PM. The 636 nm in the visible region and the 784 nm in the near-infrared region were finally assured to develop a new vegetation index (NDVI1) according to the generation mechanism of normalized difference vegetation index (NDVI). Besides, a total of ten other vegetation indices commonly used in previous studies were calculated for comparatively evaluating the performance of NDVI1. Two types of sample data (only diseased samples, and both diseased and healthy samples) and three classifiers were comparatively used to estimate the disease, including a linear regression, support vector machine (SVM) and least squares support vector machine (LS-SVM) models. The results show that the linear regression model based on the NDVI1 except for the Modified Simple Ratio (MSR) is generally the best for the two sample types, giving a coefficient of determination (R²) of 0.75 and 0.49, respectively. Conversely, the SVM and LS-SVM models provide the best estimation accuracy using the K-fold cross-validation. In general, the overall classification accuracy of the SVM is higher than that of the LS-SVM, but the LS-SVM is more efficient regarding running time. The results of this study can provide a useful guideline for wheat PM estimation using the ground-based hyperspectral data.
Computing autocorrelation coefficient can effectively reduce the influence of additive white noise, thus estimation precision will be improved. In this paper, an autocorrelation-like function, ...different from the ordinary one, is defined, and is proven to own better linear predictive performance. Two algorithms for signal model are developed to achieve frequency estimates. We analyze the theoretical properties of the algorithms in the additive white Gaussian noise. The simulation results match with the theoretical values well in the sense of mean square error. The proposed algorithms compare with existing estimators, are closer to the Cramer-Rao bound (CRLB). In addition, computer simulations demonstrate that the proposed algorithms provide high accuracy and good anti-noise capability.
It is highly important to accurately monitor wheat scab and provide technical guidance for the crop pests and diseases. In this study, relevant analysis was performed among spectral reflectance, ...first-derivate data, and the disease severity data through ASD hyperspectral data. Two sensitive spectral wavelength ranges of 450–488 nm and 500–540 nm were selected. Then, a new wheat scab index (WSI) consisting of the two bands was proposed. The inversion models of the scab severities were comparatively built by unitary linear regression and multiple stepwise regression techniques. The results showed that the WSI had a significant linear relationship with severity of disease compared with other commonly used spectral indices. The fitting R2, testing R2, and RMSE were 0.73, 0.70, and 13.41, respectively. The multiple stepwise regression model established using the WSI, SDg/SDb, NBNDVI, and SDg as independent variables was better than the single-variable model. Our results suggest that WSI can be used to provide scientific guidance for monitoring and precise management of wheat scab disease.
The genetic contribution to coronary artery disease (CAD) remains largely unclear. We combined genetic screening with functional characterizations to identify novel loci and candidate genes for CAD.
...We performed genome-wide screening followed by multicenter validation in 8 cohorts consisting of 21 828 participants of Han ethnicity and identified 3 novel intragenic SNPs (single nucleotide polymorphisms), rs9486729 (
Scm polycomb group protein-like 4; odds ratio, 1.25; 95% CI, 1.17-1.34;
=3.51×10
), rs17165136 (
thrombospondin type 1 domain-containing 7A; odds ratio 1.28; 95% CI, 1.21-1.35;
<1.00×10
), and rs852787 (
disabled-1; odds ratio, 1.29; 95% CI, 1.21-1.38;
=2.02×10
), associated with CAD with genome-wide significance. The risk allele of rs9486729 and protective allele of rs17165136 were associated with the decreased expression of their host genes,
and
, respectively, whereas rs852787 did not have transcriptional effects on any gene. Knockdown of
activated endothelial cells by increasing the expression of
,
, and
and weakened their antiapoptotic activity, whereas the knockdown of
had little effect on these endothelial cell functions but attenuated monocyte adhesion via decreasing the expression of
,
, and
. We further showed that inhibiting the expression of
exacerbated endothelial dysfunction and vascular remodeling in a rat model with partial carotid ligation.
We identify 3 novel loci associated with CAD and show that 2 genes,
and
, make functional contributions to atherosclerosis. How rs852787 and its host gene
are linked to CAD needs further studies.
Affymetrix SNP arrays have been widely used for single-nucleotide polymorphism (SNP) genotype calling and DNA copy number variation inference. Although numerous methods have achieved high accuracy in ...these fields, most studies have paid little attention to the modeling of hybridization of probes to off-target allele sequences, which can affect the accuracy greatly. In this study, we address this issue and demonstrate that hybridization with mismatch nucleotides (HWMMN) occurs in all SNP probe-sets and has a critical effect on the estimation of allelic concentrations (ACs). We study sequence binding through binding free energy and then binding affinity, and develop a probe intensity composite representation (PICR) model. The PICR model allows the estimation of ACs at a given SNP through statistical regression. Furthermore, we demonstrate with cell-line data of known true copy numbers that the PICR model can achieve reasonable accuracy in copy number estimation at a single SNP locus, by using the ratio of the estimated AC of each sample to that of the reference sample, and can reveal subtle genotype structure of SNPs at abnormal loci. We also demonstrate with HapMap data that the PICR model yields accurate SNP genotype calls consistently across samples, laboratories and even across array platforms.
Interlayer rotation in van der Waals (vdW) materials offers great potential
for manipulating phonon dynamics and heat flow in advanced electronics with
ever higher compactness and power density. ...However, despite extensive
theoretical efforts in recent years, experimental measurements remain scarce
especially due to the critical challenges of preparing single-crystalline
twisted interfaces and probing interfacial thermal transport with sufficient
resolution. Here, we exploited the intrinsic twisted interfaces in highly
oriented pyrolytic graphite (HOPG). By developing novel experimental schemes
based on microfabricated mesas, we managed to achieve simultaneous mechanical
characterizations and thermal measurements. In particular, we pushed the HOPG
mesas with a microprobe to identify and rotate single-crystalline intrinsic
interfaces owing to their slippery nature as is well known in structural
superlubricity. Remarkably, we observed over 30-fold suppression of thermal
conductance for the slippery interfaces by using epitaxial graphite as a
control. Nonetheless, the interfacial conductance remains around 600
$\mathrm{MWm^{-2}K^{-1}}$ which surpasses the highest values for artificially
stacked vdW structures by more than five times. Further, atomic simulations
revealed the predominant role of the transverse acoustic phonons. Together, our
findings highlight a general physical picture that directly correlates
interfacial thermal transport with sliding resistance, and lay the foundation
for twist-enabled thermal management which are particularly beneficial to
twistronics and slidetronics.
Control system and elastic scheduling co-design Chenggang Qin; Dong Yu; Wenjiang Wu ...
The 2010 IEEE International Conference on Information and Automation,
2010-June
Conference Proceeding
As the control systems' dynamic property and the high requirement for real-time, the traditional real-time scheduling algorithms cannot adapt to the control system. Fortunately the adaptive ...closed-loop real-time scheduling algorithms behave robustly for disturbances. This paper discusses a new feedback real-time scheduling algorithm which can adapt to the special requirements of control system. The aim of this algorithm is to guarantee the QoC (Quality of Control) and to increase the reliability of control system. It allocates resource to tasks according their contribution to QoC. The scheduling algorithm and control system co-design involves how to assign the properties of real-time tasks. Take the CNC system as an example, this paper also represents the method of scheduling algorithm and control system co-design.
Humans rely on the feedbacks they received from a teacher in learning a new motor skill. Tactile feedback is effective in motor learning as it is direct and real-time. We proposed a 3D Orientation ...Guide (3DOG) which is made up of three coin-sized vibrating motors (tactors) to create meaningful tactile feedback to give users easily interpreted instruction on how to adjust their forearm postures and inform users of the correct forearm motion. The tactors are circling around the forearm and each tactor is assigned two vibration patterns corresponding to an axial movement in positive and negative directions respectively. The layout and vibration pattern design is evaluated through the usability test. 3DOG is proved to be able to create an intuitive tactile feedback which directs motion effectively. When it is integrated with a motion capture system, the device can track and correct body postures that has application in diverse areas, such as rehabilitation, assisting learning motor skills that have requirement for movements with high accuracy. 3DOG has a promising future because of its wearability, effectiveness, small size, and low cost.
Hyperspectral reflectance of normal and lodged rice caused by rice brown planthopper and rice panicle blast was measured at the canopy level. Over one decade broad- and narrow-band vegetation indices ...(VIs) were calculated to simulate Landsat ETM+ with in situ hyperspectral reflectance. Principal component analysis (PCA) was utilized to obtain the front two principal components (PCs). Probabilistic neural network (PNN) was employed to classify the lodged and normal rice with VIs and PCs as the input vectors. PCs had 100% of overall accuracy and 1 of Kappa coefficient for the training dataset. While PCs had the greatest average overall accuracy (97.8%) and Kappa coefficient (0.955) for the two testing datasets than VIs consisting of broad- and narrow-bands. The results indicated that hyperspectral remote sensing with PCA and artificial neural networks could potentially be applied to discriminate lodged crops from normal ones at regional and large spatial scales.
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